This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. SMC complexes are conserved and essential multiprotein complexes important for higher order chormatin structural organization in mitosis, gene regulation and DNA repair. In collaboration with Dr. Berns'laboratory, we are studying the mechanism and regulation of DNA damage recognition by SMC complexes. We found that near IR laser at the BLI is uniquely suited for detecting the recruitment of one of the SMC complexes to damage sites. We plan to study the recruitment kinetics and factor requirement using the system. The study will provides important insight into the role of chromatin regulators in DNA repair, which may serve as possible therapeutic targets for cancer treatment in the future.